Chair type stretching apparatus

ABSTRACT

A chair type stretching apparatus in this invention comprises a seat, a backrest, a flexible sheet, a tension means, and a controller. The flexible sheet is disposed on a top of the seat to extend an entire width of the seat. The tension means is provided on the seat and is configured to apply tensional force to the flexible sheet so as to move a center of the flexible sheet toward an upper direction of the seat. The controller is configured to control the tension means in order to move the center of the flexible sheet to a vertical direction. The tension means is provided on at least one width end of the seat in order to apply the tensional force along a width direction of the seat to the flexible sheet, whereby the tension means moves the center of the flexible sheet to the vertical direction.

TECHNICAL FIELD

This invention relates to chair type stretching apparatus which have seats and backrests. Particularly, this invention relates to a chair type stretching apparatus which is configured to give a stretch to a back and a lower back of the user.

BACKGROUND ART

Japanese patent application publication No. 2002-119558A discloses a prior chair type stretching apparatus. The prior chair type stretching apparatus has a seat and a backrest. The chair type stretching apparatus is configured to give the stretch to the user who sits on the seat and leans against the backrest. The chair type stretching apparatus has a plurality of air-bags which are disposed on a front surface of the backrest, and are disposed on the top surface of the seat. The air-bags are configured to expand and contract, whereby the chair type stretching apparatus gives the stretch to the user, by means of the air-bags.

However, the air-bags of the prior chair type stretching apparatus has two functions. One function is to support the user, and the other function is to press the user's body. Therefore, the chair type stretching apparatus is not capable of supporting the user's body may not press the user's body according to the user's body size. Consequently, there is a problem that the air-bags of the prior chair type stretching apparatus gives the stretch to a desired portion of the user.

DISCLOSURE OF THE INVENTION

This invention is achieved to solve the above problem. An object in this invention is to provide a chair type stretching apparatus being configured to give the stretch to the user certainly regardless of the user's body size.

In order to solve the above problem, the chair type stretching apparatus in this invention comprises a seat, a backrest, a flexible sheet, a tension means, and a controller. The seat has a depth and a width which respectively have individual widths along a width of a user's body. The flexible sheet is disposed on a top of the seat. The flexible sheet extends an entire width of the seat for supporting the user's buttocks. The flexible sheet is configured to be movable between a normal position and a projected position. When the flexible sheet is positioned in the normal position, the flexible sheet lies in a close relation with a top surface of the seat. When the flexible sheet is positioned in the projected position, the flexible sheet is spaced away from the top surface of the seat. The tension means is provided on the seat. The tension means is configured to apply tensional force to the flexible sheet so as to move a center of the flexible sheet toward an upper direction of the seat. The controller is configured to control the tension means in order to move the center of the flexible sheet to a vertical direction. The tension means is provided on at least one width end of the seat in order to apply the tensional force along a width direction of the seat to the flexible sheet. Consequently, the tensional means moves the center of the flexible sheet to the vertical direction.

This chair type stretching apparatus is configured to move the user's buttock to the upper direction by means of the flexible sheet. Therefore, the chair type stretching apparatus is configured to give the stretch to the user certainly regardless of the user's body size. In addition, the tension means is disposed on at least one width end of the top surface of the seat. Therefore, the chair type stretching apparatus with the tension means is capable of achieving the reduction of the cost and the reduction of the size of the chair type stretching apparatus.

It is preferred that the tension means is defined by a pressurizing means. The pressurizing means is configured to apply pressure along the upper direction of the seat to the flexible sheet. The pressurizing means is located between the seat and the flexible sheet. Consequently, the pressurizing means moves the center of the flexible sheet toward the upper direction. The controller is configured to control the pressurizing means so as to move the center of the flexible sheet along the vertical direction of the seat. The pressurizing means is disposed on both width ends of the seat in order to apply the pressure toward the upper direction of the seat to the flexible sheet. Consequently, the pressurizing means moving the center of the flexible sheet toward the upper direction with respect to the seat.

The chair type stretching apparatus is also configured to move the user's buttock to the upper direction. Therefore, the chair type stretching apparatus is configured to give the stretch to the user certainly regardless of the user's body size.

It is preferred that the flexible sheet has a front end and a rear end. The front end of the flexible sheet is fixed to a front end of the seat. The rear end of the flexible sheet is attached to a rear end of the seat to be movable in the vertical direction of the seat.

In this case, the flexible sheet is located at a portion faced to the user's buttock. Therefore, this configuration makes it possible for the chair type stretching apparatus to give the stretch to the user's buttocks effectively.

It is preferred that the flexible sheet is made of a hard foamed material.

This configuration makes it possible to reduce the contact force with respect to the user's buttocks. In addition, this configuration also makes it possible for the chair type stretching apparatus to give the stretch to the user effectively.

It is preferred that the flexible sheet and the pressurizing means are detachably attached to the seat.

In this case, it is possible to vary the position of the flexible sheet and the pressurizing means on the top surface of the seat. Therefore, this configuration makes it possible for the chair type stretching apparatus being configured to give the stretch to a desired portion of the user's body.

It is preferred that the chair type stretching apparatus comprises a stretching unit. The stretching unit is detachably attached to the top surface of the seat. The stretching unit is provided at its top surface with the flexible sheet. The stretching unit is provided at its both width ends of an inside of the stretching unit with the pressurizing means. Consequently, the flexible sheet and the pressurizing means are detachably attached to the seat.

In this case, it is possible to vary the position of the flexible sheet and the pressurizing means on the top surface of the seat. Therefore, this configuration makes it possible for the chair type stretching apparatus to give the stretch to the desired portion of the user's body.

It is preferred that the flexible sheet has both width ends which are respectively attached to both width surfaces of the seat. At least one width end of the flexible sheet is detachable attached to a predetermined area of the width surface of the seat.

In this case, it is possible to vary an amount of a slack of the flexible sheet in the width direction. Therefore, this configuration makes it possible to vary intensity of the stretch given to the user.

It is preferred that the pressurizing means is composed of air-bags and the pump. The air-bags are configured to expand and contract along the vertical direction. The pump is configured to send the air to the air-bag.

In this case, when the chair type stretching apparatus is stopped, the air-bags are contracted. Therefore, this configuration makes it possible to reduce the size of the chair type stretching apparatus.

It is preferred that the chair type stretching apparatus comprises a wall. The wall is located between the seat and the flexible sheet. The wall is located at one width end of the top surface of the seat. The tension means is defined by a pressurizing means. The pressurizing means is configured to apply pressure along the upper direction of the seat to the flexible sheet. The tension means is located between the seat and the flexible sheet so that the tension means moves the center of the flexible sheet. The controller is configured to control the pressurizing means in order to move the center of the flexible sheet toward the vertical direction of the seat. The pressurizing means is located at one width end of the seat such that the pressurizing means is located away from the wall. The pressurizing means is configured to apply the pressure along the upper direction of the seat to one end of the flexible sheet so that the pressurizing means applies the tensional force directed outwardly of a width direction to the flexible sheet.

In this case, the chair type stretching apparatus is configured to move the user's buttocks to the upper direction by means of the flexible sheet. Therefore, this configuration makes it possible to the chair type stretching apparatus to give the massage to the user's body certainly regardless of the user's body size.

It is preferred that the chair type stretching apparatus comprises walls. The walls are located between the seat and the flexible sheet. The walls are located at both width ends of the top surface of the seat. The tension means is defined by rollers. The rollers respectively hold width ends of the flexible sheet. The rollers are configured to wrap the flexible sheet around the rollers so that the rollers move the center of the flexible sheet toward the upper direction of the seat. The controller is configured to control the rollers in order to move the center of the flexible sheet to the vertical direction. The rollers are disposed on both the width surfaces of the seat. The rollers are configured to wrap the flexible sheet. Consequently, the rollers apply the tensional force directed outwardly of a width direction to the flexible sheet.

In this case, the chair type stretching apparatus is configured to move the user's buttocks to the upper direction by means of the flexible sheet. Therefore, it is possible to obtain the chair type stretching apparatus being configured to give the stretch to the user certainly regardless of the user's body size.

Further characteristics of the present invention and effects resulting there from can be better understood based on the best mode for carrying out the invention and examples thereof described below.

BRIEF EXPLANATION OF THE DRAWINGS

FIG. 1 (a) shows a perspective view of a chair type stretching apparatus in a first embodiment.

FIG. 1 (b) shows a perspective view of the chair type stretching apparatus in the first embodiment without flexible sheets, pressurizing means, and an applicator cover.

FIG. 2 (a) shows a side view of the chair type stretching apparatus in the first embodiment having a normal condition.

FIG. 2 (b) shows a side view of the chair type stretching apparatus in the first embodiment having the backrest which has a reclining condition.

FIG. 3 (a) shows a side view of the chair type stretching apparatus having the seat. The air-bags on the seat are expanded.

FIG. 3 (b) shows a side view of the chair type stretching apparatus having the backrest. The air-bags on the backrest are expanded.

FIG. 4 (a) shows a perspective view of a chair type stretching apparatus of a first modification having the backrest and the seat. The air-bag on the left side of the backrest and the air-bag on the left side of the seat are expanded.

FIG. 4 (b) shows a perspective view of a chair type stretching apparatus of the first modification having the backrest and the seat. The air-bag on the left side of the backrest and the air-bag on the right side of the seat are expanded.

FIG. 5 (a) shows a top view of the chair type stretching apparatus having the contracted air-bags which are disposed on the lateral end of the front surface of the backrest.

FIG. 5 (b) shows a top view of the chair type stretching apparatus having the expanded air-bags which are disposed on the lateral end of the front surface of the backrest.

FIG. 5 (c) shows a top view of the chair type stretching apparatus having the expanded air-bag which is disposed on the left side of the front surface of the backrest.

FIG. 6 shows a front view of the above.

FIG. 7 (a) is a front schematic view of the chair type stretching apparatus in the second modification. In FIG. 7 (a), the air-bags on the both lateral ends of the top surface of the seat are contracted.

FIG. 7 (b) shows a front schematic view of the chair type stretching apparatus in the second modification. In FIG. 7 (b), the air-bags on the both lateral ends of the top surface of the seat are expanded.

FIG. 8 shows a schematic view of controller, pump, electromagnetic valves, and the air-bags.

FIG. 9 shows a front view of the chair type stretching apparatus in the modification.

FIG. 10 shows a front cross sectional view of the seat in a third modification.

FIG. 11 (a) shows a front cross sectional view of the seat in a fourth modification. In FIG. 11 (a), the air-bags are contracted.

FIG. 11 (b) shows a front cross sectional view of the seat in the fourth modification. In FIG. 11 (b), the air-bags are expanded.

FIG. 12 (a) shows a top cross sectional view of the chair type stretching apparatus in a fifth modification. In FIG. 12 (a), the flexible sheet is slacked.

FIG. 12 (b) shows a top cross sectional view of the chair type stretching apparatus in the fifth modification. In FIG. 12 (b), flexible sheet is wrapped by the roller.

FIG. 13 (a) and FIG. 13 (b) shows a side cross sectional view of a chair type stretching apparatus in the sixth modification.

BEST MODE FOR CARRYING OUT THE INVENTION First Embodiment

A chair type stretching apparatus in this invention is explained with attached drawings. In FIG. 1, an arrowed line directed to X indicates the front direction of the chair type stretching apparatus. An arrowed line directed to Y indicates the left direction. An arrowed line directed to Z direction indicates the upper direction. That is, the chair type stretching apparatus 100 has a width direction which is equivalent to the lateral direction of the chair type stretching apparatus. The chair type stretching apparatus 100 has a depth direction which is equivalent to the front-back direction of the chair type stretching apparatus. The chair type stretching apparatus 100 has a vertical direction which is equivalent to the height direction.

FIG. 1 (a) shows a perspective view of the chair type stretching apparatus 100 in the first embodiment. As shown in FIG. 1 (a), the chair type stretching apparatus 100 in this embodiment comprises a base 200, a seat 300, a backrest 400, arm rests 900, and a foot rest 901. The base 200 is shaped to support the seat 300, the backrest 400, the arm rests 900, and the footrest 901. The base has a front surface which supports the footrest 901. The base 200 is provided at its top surface with the seat 300. The base 200 has a rear surface which supports the backrest 400 extending toward an upper direction of the base 200. The base 200 is provided at its both lateral surfaces with arm rests 900, respectively. The base 200 incorporates a pump 220 and a controller 240. The pump 220 and the controller 240 are configured to be operated when the pump 220 and the controller 240 receive electrical power. The chair type stretching apparatus 100 has a reclining mechanism (not shown) of reclining the backrest 400. In addition, the chair type stretching apparatus 100 is provided with an operation device which is not shown. The operation device is used for setting the operation of the pump 220.

The backrest 400 has a width along a lateral direction. In other words, the backrest 400 has the width along a width of the body of the user. As shown in FIG. 1 (a), the backrest 400 includes an applicator cover 410, an air-bag 420, an air bag 430, a flexible sheet 421, and a flexible sheet 431. FIG. 1 (b) shows the chair type stretching apparatus 1 without the applicator 410, the flexible sheet 421, the flexible sheet 431, the air-bag 420, and the air-bag 430. As shown in FIG. 1 (b), the backrest 400 is formed at its front surface with an opening 440. The opening 440 extends along a height direction of the backrest 400.

The backrest 400 includes applicators 441, arms 442, and a massaging device 443. The applicator 441, the arms 442, and the massaging device 443 are disposed within the opening 440. The arms 442 have front ends which respectively hold the applicators 441. The massaging device 443 holds rear ends of the arms 442. The massaging device 443 is activated upon receiving the electrical power. In addition, FIG. 2 (a) shows a side cross sectional view of the chair type stretching apparatus 100. As shown in FIG. 2 (a), the backrest 400 includes a guide rail 444. The guide rail 444 is provided for sliding the massaging device 443 along the guide rail 444. The guide rail 444 is disposed within the backrest 400 and extends along a vertical direction. Consequently, the massaging device 443 moves along the height direction within the opening 440. Each of the flexible sheet 421 and the flexible sheet 431 has slack. The flexible sheets 421 and 431 cover the opening 440 in order to conceal the massaging device 443, the arms 442, and the applicators 441.

The air-bags 420 are respectively disposed on the front surface of the backrest 400 and respectively located at both width ends of the backrest 400. The air-bags 430 are respectively disposed on the front surface of the backrest 400 and respectively located at both width ends of the backrest 400. The air-bags 420 and the air-bags 430 are arranged along a height direction of the backrest. The air-bag 420 and 430 are respectively shaped to have bellows. The air-bags 420 and 430 have bottom surfaces which are respectively attached to the front surface of the backrest 40 by the snap pin. The air-bags 420 and 430 are connected to the pump 220 through the hoses 230 respectively, shown in FIG. 8. The pump 220 is configured to send the air to the air-bags 420 and 430. The air-bags 420 and 430 are configured to expand when the air is sent from the pump 220. Because the air-bags 420 and 430 are arranged on the front surface of the backrest 440, the air-bags 420 and 430 expand toward the front direction of the backrest upon receiving the air. On the other hand, the air-bags 420 and 430 is contracted toward the backrest when the air in the air-bags 420 and 430 is released.

Each one of the flexible sheets 421 and 431 is made of a cloth. The flexible sheets 421 and 431 are disposed in normal positions of lying in a close relation with a front surface of the backrest. The flexible sheets 421 and 431 are located in front of the air-bags 420, 430. The flexible sheets 421 and 431 are provided on the backrest 400 so as to extend over an entire width of the backrest 400. The flexible sheets 421 and 431 respectively have both lateral ends. Both lateral ends of the flexible sheets 421 and 431 are sewed on width side surfaces of the backrest 400. The air-bags 420 and 430 are respectively provided at its front surface with loop tapes. On the other hand, the flexible sheets 421 and 431 are respectively provided at its rear surface with hook tapes. Consequently, the air-bags 420 have the front surfaces which are fastened to the rear surface of the flexible sheet 420 by means of hook-and-loop fastener. Similarly, the air-bags 430 have the front surfaces which are fastened to the rear surface of the flexible sheet 431 by means of hook-and-loop fastener. The flexible sheet 421 has its width center which is faced to a lower back of the user in order to support the user's lower back. The flexible sheet 431 has its width center which is faced to the back of the user in order to support the user's back.

The seat 300 has a depth along the front-back direction, and a width along the width of the user who sits on the seat 300. As shown I Fig (a), the seat 300 is provided with air-bags 310 and the flexible sheet 311.

The air-bags 310 are disposed on both width ends of the top surface of the seat 300. The air-bags 310 are respectively shaped to have bellows shown in FIG. 8. Each air-bag 310 is connected to the pump 220 through an electromagnetic valve 210 and a hose 230. The air-bag 310 has its bottom surface which is attached to the top surface of the seat 300 by means of the snap pin. The air-bag 310 is configured to expand upon receiving the air from the pump 220. Therefore, the air-bags 310 disposed on the top surface of the seat 300 are expanded toward an upper direction of the seat 300 upon the air is sent to the air-bags 310. On the other hand, the air-bags 310 disposed on the top surface of the seat 300 are contracted toward a lower direction of the seat 300 when the air is removed from the air-bags 310.

The flexible sheet 311 is made of the cloth. The flexible sheet 310 is disposed on the top surfaces of the seat 300 and the air-bags 310. The flexible sheet 310 extends over an entire width of the seat 300, and also extends over an entire depth of the seat 300. The flexible sheet 311 has its width center which is faced with the buttocks. The air-bags 310 are respectively provided at its top surfaces with loop tapes. On the other hand, the flexible sheet 311 is provided at its rear surface which is faced with the top surface of the air-bags 310. The rear surface of the flexible sheet 311 is provided with hook tapes which are not shown. Consequently, the top surface of the air-bag 310 is fastened to the rear surface of the flexible sheet 311 by means of the hook-and-loop fastener. The flexible sheet 311 has both lateral ends which are respectively sewed to the both width surface of the seat 300. It is noted that the flexible sheet 311 is preferably made of a hard foamed material.

FIG. 8 shows a controller 240 being configured to control the air-bags 420, 430, 310, the electromagnetic valves 210, and the pump 220. The controller 240 includes a pump control circuit 241 and the valve control circuit 242. The controller 240 sends a control signal on the basis of setting of an operation device operated by the user. When the valve control circuit 241 receives the control signal, the valve control circuit 242 opens and closes the electromagnetic valves 210 on the basis of the control signal. In addition, when the pump control circuit 241 receives the control signal, the pump control circuit 241 controls the pump 220 to start or stop. Consequently, the pump 220 sends the air to the air-bag 420, 430, and 310 through the hoses 230. Furthermore, the controller 240 controls the valve control circuit 242 and the pump control circuit 241 respectively in order to expand and contract the air-bags 420, 430, 310.

The chair type stretching apparatus 100 operates as follows. When the setting is entered by the operation device, the controller 340 controls the pump 220 and the electromagnetic valves 210 in order to send the air to the air-bags 420 and 430. Because the air-bags 420 and 430 are disposed on the front surface of the backrest 400, the air-bags 420 and 430 expands toward the front direction of the backrest 400. Consequently, the air-bags 420 and 430 apply the force along the front direction of the backrest 400 to the both width ends of the flexible sheets 421 and 431. That is, the air-bag 420 and 430 act as pressurizing means being configured to apply the force toward the front direction of the backrest to the flexible sheets 421 and 431. Both the lateral ends of the flexible sheets 421 and 431 are sewed to the both width surfaces of the backrest 400. Therefore, the air-bags 420, 430 generates the tensional force along outwardly the width direction of the flexible sheets 420 and 430 according to the expansion of the air-bags 420 and 430. That is, the air-bags 420 and 430 act as the tension means which is configured to generate the tensional force which are along the flexible sheets 420 and 430 and which are applied to the flexible sheets 420 and 430. When the air-bags 420 and 430 applies the tensional force along the lateral direction of the flexible sheet 421, 431, the air-bags 420 and 430 moves the lateral center of the flexible sheets 421 and 431 to front-back directions.

In addition, on the basis of the setting of the operation device, the controller 240 controls the pump 220 and the electromagnetic valves 210, whereby the pump 220 sends the air to the air-bag 310. The air-bags 310 are disposed on the top surface of the seat 300. Therefore, the air-bags 310 expand toward the upper direction of the seat 300. Consequently, the air-bags 310 apply the force toward the upper direction of the seat 300 to both the width ends of the flexible sheet 310 on the seat 300. That is, the air-bags 310 act as the pressurizing means for applying the pressure toward the upper direction of the seat 311. Both the width ends of the flexible sheet 311 are sewed to both the lateral surface of the seat 300. Therefore, when the air-bags 310 are expanded, the air-bags 310 generate the tensional force along outwardly the width direction of the flexible sheet 311. That is, the air-bags 310 act as the tension means being configured to generate the tensional force which is along the width direction of the seat and which is applied to the flexible sheet 310. The air-bags 310 move the width center of the flexible sheet 311 toward the upper direction by applying the tensional force along the lateral direction of the flexible sheet 311 to the flexible sheet 311.

The chair type stretching device 100 with this configuration makes it possible to give the stretch to the user who sits on the seat and leans against the backrest. FIG. 3 (b) shows the chair type stretching device 100 which moves the user's lower back by controlling the air-bags 430 which is disposed on the position corresponding to the user's lower back. In addition, FIG. 3 (a) shows the chair type stretching device 100 which moves the user's buttock by controlling the air-bags 310 which is disposed on the position corresponding to the user's buttocks.

FIG. 4 shows a chair type stretching apparatus 100 of a first modification of the first embodiment. In this modification, the backrest 400 includes the air-bags 420 (420L and 420R), and the flexible sheet 421. The air-bags 420L and 420R are disposed on backrest 400 to be located at a position corresponding to the user's back. The flexible sheet 421 is disposed on the backrest 400 to be located at a position being faced to the user's back. The seat 300 includes the air-bags 310 (310L and 310R) and the flexible sheet 311. As shown in FIG. 4 (a), the air-bag 420L and 310L are respectively disposed on the left side of the backrest 400 and the left side of the seat 300. The pump 220 sends the air to the air-bag 420L and 310L. Consequently, the flexible sheets 421 and 311 respectively have left ends which are located in the projected positions with respect to the backrest 400 and the seat 300. Therefore, the chair type stretching apparatus 100 gives the stretch of turning of the user to the right about an axis along a height of the user.

In addition, as shown in FIG. 4 (b), the pump 220 sends the air to the air-bag 421L disposed on the left side of the backrest 400. Consequently, the flexible sheet 421 has its left end being located in the projected position. On the other hand, the pump 220 sends the air to the air-bag 310R disposed on the right side of the backrest 400. Consequently, the flexible sheet 311 has its right end being located in the projected position. Therefore, the flexible sheet 421 and 311 gives the stretch to the user sitting on the chair type stretching apparatus. In particular, the chair type stretching apparatus turns the user's upper body to the right about the axis along a height of the user. On the other hand, the chair type stretching apparatus turns the user's lower body to the left about the axis along the height of the user. Consequently, this configuration makes it possible for the chair type stretching apparatus to give the stretch of twisting an upper body of the user with respect to the lower body.

FIG. 5 shows a top view of the first embodiment and the first modification of the chair type stretching apparatus. FIG. 5 shows the condition of the user's upper body with respect to the chair type stretching apparatus. As shown in FIG. 5 (b), the chair type stretching apparatus with the above configuration is configured to move the user's upper body toward the front position regardless of the width of the body of the user. In addition, as shown in FIG. 5 (c), the chair type stretching apparatus with this configuration may turn the user's body to the right regardless of the width of the body of the user.

FIG. 9 shows a chair type stretching apparatus of a second modification of the first embodiment. In this modification, the chair type stretching apparatus comprises a stretching unit 350. The stretching unit 350 is provided at its top surface with a flexible sheet. The stretching unit 350 is shaped to have a sack. The air-bags 310 are disposed within the stretching unit 350.

The stretching unit 350 of this modification is shaped to cover an entire top surface of the seat 300. The stretching unit 350 is provided at its front end with the fastener 351. That is, the stretching unit 350 is detachably attached to the seat 300 by mean of the fastener 351.

The stretching unit 350 includes a hose 230 which is communicated with the air-bags 310. The hose 230 is pulled outwardly from the width surface of the stretching unit 350. The hose 230 has its one end with a connecting port (not shown) which is connected to the pump 220. The pump 220 is configured to send the air to the air-bags 310 through the hose 230.

Therefore, when the stretching unit 350 having the flexible sheet 311 is disposed in a close relation to a top surface of the backrest 400, the air-bags 350 are respectively configured to apply tensional force along the lateral direction to the flexible sheet according to the expansion of the air-bags 310. Consequently, it is possible to obtain the chair type stretching apparatus being configured to give the stretch to the user. It is noted that the stretching unit 350 preferably has a plurality of fasteners 451 each of which extend along the lateral direction to form a plurality of lines. In this case, it is possible to select the one line of the fasteners for attaching the stretching unit 350 to the seat 300. Consequently, the vertical position of the stretching unit 350 is varied. In addition, it is also possible to detach the stretching unit 350 from the seat 300 when the chair type stretching apparatus needs to give no stretch to the user.

FIG. 10 shows a chair type stretching apparatus of a third modification of the first embodiment. In this modification, the flexible sheet 311 is provided at its both lateral ends of the rear surface with the hook tapes (not shown). The seat 300 is provided at its both lateral surfaces with certain areas. The certain areas hold the loop tapes 312, respectively. Consequently, the flexible sheet 311 is detachably attached to both the lateral surfaces of the backrest 400.

Therefore, the chair type stretching apparatus is configured to give the stretch to the user when the flexible sheet 311 is disposed on the seat 300 and also the air-bags 310 are expanded. In addition, the loop tapes 312 are disposed on the certain areas of the both lateral surface of the seat 300. Therefore, the flexible sheet 311 has both lateral ends which are respectively detachably attached to the certain areas of the both lateral surfaces of the seat 300. Consequently, it is possible to vary slack in the lateral direction of the flexible sheet 311. As a result, it is possible to adjust intensity of the stretch which is given to the user. In addition, the flexible sheet 311 is movable along a front-back direction. Therefore, it is possible to adjust the position for giving the stretch to the user. It is noted that it is only required for the flexible sheet 311 to have one lateral end which is detachably attached to the seat 300.

FIG. 11 shows a fourth modification of the first embodiment of the chair type stretching apparatus. In this modification, the seat 300 is provided at its left end of the top surface with a wall 380 instead of the air-bag. The seat 300 is provided at its right end of the top surface with the air-bag 310. The flexible sheet 421 is located on the wall 380 and the air-bag 310. The left end of the flexible sheet 311 is fixed to a top end of the wall 380. The right end of the flexible sheet 311 is fixed to the right side surface of the backrest 300. When the air-bag 310 is expanded, the top front end of the air-bag 310 is moved to a position in the vertical direction. As a result, the top end of the air-bag 310 is located at a level same as the level of the top end of the wall 480.

With this configuration, as shown in FIG. 11 (b), when the air-bag 310 is expanded, the air-bag 310 applies the tensional force along the lateral direction of the flexible sheet 311 to the flexible sheet 311. When the tensional force is applied to the flexible sheet 311, the width center of the flexible sheet 311 is moved toward to upper direction. As a result, the flexible sheet 311 moves a portion of the user corresponding to the lateral center of the flexible sheet 311. That is, the flexible sheet 311 moves the user's buttocks toward the upper direction. As a result, the chair type stretching apparatus gives the stretch to the user. In addition, when the air-bag 310 is contracted as shown in FIG. 11 (a), the flexible sheet 311 has a slack condition. As a result, the flexible sheet is moved toward a normal position, thereby the user's buttocks are moved toward a position along the seat 300. It is noted that seat 300 in this modification is provided at its left end with the wall 380, and is provided at its right end with the air-bag 310. However, it is possible to employ the seat 300 which is provided at its right end with the wall, and is provided at its left end with the air-bag.

FIG. 12 shows a fifth modification of the embodiment of the chair type stretching apparatus. In this modification, the seat 300 has the walls 380 and rollers 390 instead of the air-bags. That is, the seat 300 is provided at its both lateral end of the front surface with the walls 380. Both the walls 380 extend toward the upper direction of the seat 300. The rollers 390 are disposed on both the lateral surfaces of the seat 300. The walls 380 are located between the flexible sheet 311 and the seat 300. The rollers 390 hold the both lateral ends of the flexible sheets 311. Both the rollers 390 are configured to wrap the flexible sheet 311, thereby generating the tensional force along the lateral direction of the flexible sheet 311. That is, the rollers 390 act as the tension means.

The controller 240 is configured to control the roller 390 such that the rollers 390 wrap the flexible sheet 311. Consequently, the rollers 390 apply the tensional force along the lateral direction of the flexible sheet 311. Therefore, the rollers 390 move the width center of the flexible sheet to the front direction. As a result, the flexible sheet 311 moves the portion of the user corresponding to the width center of the flexible sheet 311. Consequently, the chair type stretching apparatus gives the stretch to the user.

Next a modification of the seat 300 with using the air-bag is explained.

FIG. 13 (a) shows a sixth modification of the chair type stretching apparatus. As shown in FIG. 13 (a), the seat 300 is provided with the air-bag 310 and a plate 500. The plate 500 is fixed on the front end of the air-bag 310. The plate 500 is hard. A front surface of the plate 500 holds the flexible sheet 311. Furthermore, the plate 500 has both horizontal ends which are respectively rotatably fixed to one ends of the support members 510, 520. The seat 300 rotatably supports the front end of the support member 520. The seat 300 is provided at its top surface with the slide member 540. The slide member 540 rotatably supports the rear end of the support member 510, and also slidably supports the rear end of the support member 510.

When the air-bag 310 receives the air from the pump, the slide member 540 slides the rear end of the support member 510 toward a front direction. According to movement of the rear end of the support member 510, the rear end of the support member 510 rotates such that the support member 510 allows the plate 510 to move toward the upper direction. As a result, the plate 510 applies the tensional force along the width direction to the flexible sheet 421. Therefore, the user applies the force to the air-bag 310 and the plate 500. The support members 510 and 520 gradually stand with respect to the top surface of the seat 300. As a result, a large ratio of the force applied from the user to the air-bag 310 and the plate 500 is supported by the support members 510 and 520. That is, a ratio of the force applied from the user to the air-bag 420 is reduced. Thus, this configuration makes it possible to move the user's buttocks toward the upper direction with low force.

In the seventh modification shown in FIG. 13 (b), one end of a support member 530 is rotatably supported by the top surface of the seat 300, and the other end of the support member 530 is fixed to the flexible sheet 311. The top surface of the seat 300 holds the bottom surface of the air-bags 310 having the bellows. The top surface of the air-bags 310 is fixed to a portion between a portion of the support member 530 and the flexible sheet 311.

When the air-bag 310 receives the air from the pump 220, the air-bag 310 is expanded. According of expansion of the air-bag 310, the one end of the support member 530 is moved toward the front direction, while the other end of the support member 530 is rotated. In this case, the air-bag 310 moves the flexible sheet 311 by the force generated by the principle of leverage and large stroke. Therefore, the air-bag 310 is capable of applying the tensional force to the flexible sheet.

Although the present invention is described with particular reference to the above illustrated embodiment and modifications, the present invention should not be limited thereto, and should be interpreted to encompass any combinations of the individual features of the embodiment and modifications. 

1. A chair type stretching apparatus having a seat and a backrest which respectively have individual widths along a width of a user's body, and a depth, said stretching apparatus comprising: a flexible sheet being disposed on a top of said seat to extend an entire width of said seat for supporting the user's buttocks, said flexible sheet being configured to be movable between a normal position and a projected position, said flexible sheet in said normal position lying in a close relation with a top surface of said seat, said flexible sheet in said projected position is spaced away from said top surface of said seat, a tension means being provided on said seat and being configured to apply tensional force to said flexible sheet so as to move a center of said flexible sheet toward an upper direction of the seat, a controller being configured to control said tension means in order to move said center of said flexible sheet to a vertical direction, wherein said tension means is provided on at least one width end of said seat in order to apply the tensional force along a width direction of the seat to said flexible sheet, whereby the tension means moves the center of the flexible sheet to the vertical direction.
 2. The stretching apparatus as set forth in claim 1, wherein said tension means is defined by a pressurizing means being configured to apply pressure along the upper direction of the seat to the flexible sheet, said pressurizing means is located between the seat and the flexible sheet, thereby moving said center of said flexible sheet toward the upper direction, said controller being configured to control said pressurizing means so as to move said center of said flexible sheet along the vertical direction of the seat, said pressurizing means being disposed to both width ends of the seat in order to apply the pressure toward the upper direction of the seat to said flexible sheet, whereby said pressurizing means moving said center of said flexible sheet toward the upper direction with respect to the seat.
 3. The stretching apparatus as set forth in claim 2, wherein said flexible sheet has a front end which is fixed to a front end of said seat, and said flexible sheet has a rear end which is attached to a rear end of said seat to be movable in the vertical direction of said seat.
 4. The stretching apparatus as set forth in claim 2, wherein said flexible sheet is made of a hard foamed material.
 5. The stretching apparatus as set forth in claim 2, wherein said flexible sheet and said pressurizing means are detachably attached to said seat.
 6. The chair type stretching apparatus as set forth in claim 5 further comprises a stretching unit which is detachably attached to said top surface of said seat, said stretching unit being provided at its top surface with said flexible sheet, and being provided at its width ends of an inside of said stretching unit with said pressurizing means so that said flexible sheet and said pressurizing means are detachably attached to said backrest.
 7. The stretching apparatus as set forth in claim 2, wherein said flexible sheet has width ends which are respectively attached to both width surfaces of said seat, and at least one of said width ends of said flexible sheet being detachably attached to a predetermined area of said width surface of said seat.
 8. The stretching apparatus as set forth in claim 2, wherein said pressurizing means is composed of air-bags and a pump, said air-bags being configured to expand and contract toward the vertical direction of said seat, and said pump being configured to send air to said air-bag.
 9. A stretching apparatus as set forth in claim 1 further comprises a wall, said wall being located between said seat and said flexible sheet, and being located at one width end of said top surface of said seat, said tension means being defined by a pressurizing means being configured to apply pressure along the upper direction of the seat to said flexible sheet, said tension means being located between said seat and said flexible sheet so as to move said center of said flexible sheet, said controller being configured to control said pressurizing means in order to move said center of said flexible sheet toward said vertical direction of said seat, said pressurizing means being located at one width end of said seat and being located away from said wall, said pressurizing means being configured to apply the pressure along the upper direction of said seat to one end of said flexible sheet so that said pressurizing means applies the tensional force directed outwardly of a width direction to said flexible sheet.
 10. The stretching apparatus as set forth in claim 1 further comprises walls, said walls are located between said seat and said flexible sheet, and being located at both width ends of said top surface of said seat, said tension means is defined by rollers, said rollers respectively holding width ends of said flexible sheet, and are configured to wrap said flexible sheet around said rollers so as to move said center of said flexible sheet toward the upper direction of said seat, said controller being configured to control said rollers in order to move said center of said flexible sheet to the vertical direction, said rollers being disposed at both the width surfaces of said seat, and being configured to wrap said flexible sheet in order to apply the tensional force directed outwardly of a width direction to said flexible sheet, whereby the rollers moves the center of the flexible sheet toward the upper direction. 